1. Field of the Invention
This invention relates generally to electrical cords and connectors, and more specifically to an improved electrical extension cord having a male plug convertible between standard residential or blade-type plug elements and twist-lock blade elements, and a female receptacle plug designed to accommodate both standard and twist-lock male plugs.
2. Description of the Prior Art
Electrical cords and connectors come in many sizes and configurations. For example, standard residential electrical systems typically utilize blade-type plugs and receptacles (NEMA 5-15). However, many power tools and accessories utilize twist-lock plugs and receptacles, chiefly in order achieve a more secure connection and to reduce disconnection in active use. This disparity in connector types can cause delay and frustration, because a user of twist-lock equipment and cords must use a blade-type adapter to connect to a residential outlet, and a user of blade-type equipment and cords must use a twist-lock adapter to connect to a twist-lock receptacle or cord. It can be both inconvenient and time-consuming to locate and connect such adapters.
It is accordingly an object of this invention to provide a single plug that will couple to either a residential or a locking-type connector or receptacle.
It is a further object of this invention to provide a self-contained plug that can be converted from a residential-type connector or receptacle to a locking-type connector or receptacle and back again.
It is a still further object of this invention to provide a single system for different electrical couplings that is convenient to use and that does not require additional attachments.
It is a still further object of this invention to provide an electrical receptacle or connector that will accept either an electrical locking plug or a residential plug without the use of an adapter.
The electrical extension cord with convertible plug and accommodating receptacle of this invention provides an improved electrical extension cord having a male plug convertible between standard residential or blade-type plug elements and twist-lock blade elements, and a female receptacle plug designed to accommodate both standard and twist-lock male plugs. The inventive male plug includes a pivoting body member having a twist-lock set of blade elements on one end, and a residential or blade-type set of plug elements on the other end, such that the user can selectively rotate the body member to orient the desired set of plug elements outwards for use. The selected set of plug elements are placed in electrical contact with the corresponding common, hot, and ground wires in the extension cord by releasable capture of the terminals of the wires, as by the use of spring contacts at the base of the plug elements. The inventive female plug accommodates both blade-type and twist-lock male plugs by providing fixed, permanent receiving slots for the plug elements of each type.